Husqvarna is one of the major manufacturers of gardening and cutting equipment for the construction and stonemasonry industries. It is the world’s second largest manufacturer of chainsaws after the German company, Stihl.
1956 saw the launch of the first powered mower, followed by the first chainsaw in 1959. In addition to chainsaws, Husqvarna also produces gardening equipment and household appliances under the same name. Both of Husqvarna’s sectors have been part of the the Swedish multinational Electrolux since 2006 but the chainsaw sector is currently the company’s strongest.
Husqvarna was one of the first companies to develop a project to design a programmable robot cutter and, thanks to several patents, an extremely advanced and well-tested product has emerged.
Husqvarna’s Italian Outdoor Products factory, in Valmadrera in the province of Lecco, is an example of a company that has confronted important decisions about introducing technological complexity.
Valmadrera’s headquarters is their lawnmower production centre, and in 2011 within the framework of a Lean Transformation project – the company decided to completely review the structure of the entire lawnmower line, which was no longer technologically adequate and convertible according to Lean Thinking’s typical Flow and Pull principles, which planned to streamline production flow in relation to pull; i.e. customer or market demand.
Rather than becoming completely automated, the company decided to maintain some manual elements in combination with simple automation designed to support the operators and their work.
To be more certain of being able to realise a continuous flow of the manufacturing and assembly process, at the start of the project, all stages of lawnmower production were analysed, both the operations carried out inside the plant and those carried out externally.
Initially there were 4 synchronous assembly lines, each specific to a single product line. The purpose of the intervention was to achieve maximum flexibility and to level the lines against the peaks and troughs in the sales of a particular line.
Areas of intervention
In order to achieve this, a “mixed model” solution was created based on 2 single continuous parallel lines, symmetrical and equivalent, each capable of producing any kind of mower.
In addition, the ability for smaller production batches than in the past was made possible through “small batch flow” logic, in other words the continuous production of small groups, which is no longer subject to the demand and sales of specific models, but which is able to produce, without interruption, any pattern of the 2 lines in production.
The whole intervention was completed with a complete re-engineering of the production line, which went from being synchronous to continuous, and application of pull system logic for internal manufacturing parts.
The decoupling point, that is, the transition from push management to pull production logic was made through the introduction of a supermarket of materials which receives the semi-manufactured products (moulded bodywork of the lawnmower) and a proximity warehouse for third-party components with long supply times (caused by distance, complexity, component costs, etc.).
The plant’s welding and paintwork departments and assembly line are, therefore, supplied by the semi-finished supermarket, the nearby warehouse and the suppliers through a synchronised process.
A new system for the supply of the train line was also introduced, the so-called tugger system, with small standard batch restocking, which has allowed the model change time on the lines to be reduced to zero.
So some significant technologies were introduced, selected and implemented on the two lines to make continuous stream conditions possible, to eliminate waste and wait times on the lines themselves and to achieve maximum flexibility in terms of changing model production.
A few simple solutions have led to some very evident improvements:
- Continual advances in assembly.
- The adoption of adjustable swing-trays.
- Installing a controller for handling products while on the line.
- Semi-automated packing immediately at the end of the lines.
- Balance mode through use of prepared components to reduce difference between simple and complex models on the same line.
- “Coupling” line sections positioned outside the warehouse for the influx of bulky components (motors, handles).
The adjustable swing-trays have allowed all the operators to remain on one side of the line and the supplies on the other side in an essential configuration for the new train supply system (the tugger system).
This solution has standardised all production lines, making them ideal for hosting all models without any need for adaptation and/or adjustment when changing from one model to another.
The manipulator on the line allows the operator to upturn the mower on the swing-tray, allowing the installation of internal components with no risk to safety, exertion or back injury.
The automatic packing system, like the manipulator, completely eliminates the risks to line personnel.
Sharing the various solutions with the workforce has been done with extreme care since the early stages.
Technicians and operators have, in fact, designed solutions together with line consultants and builders, providing many ideas that have resulted in low-cost solutions in line with the defined process.
The confidence shown by the operators in the use of the chosen equipment and the technical knowledge they acquired during the project has reduced not only the time necessary to install and start the lines but also to record important improvements compared to the past.
- Reduction in the cost of manpower: -27% in the absence of “traditional automation”.
- Increase in performance indicator (OLE – Overall Labour Efficiency with the new manpower cost): +14%
- Total “door to door” lead time: -45%
- Average distance of internal handling : -30%
- Stocks on line: -65%
- Zero set-up times
Thanks to these improvements it was possible, with the same workforce levels, to insource some externally pre-assembled components and increase the plant’s overall production volumes.
“With Lenovys, we succeeded in restoring productivity after years of decline. The foresight to find simple, low-cost solutions, testing them first to avoid surprises later in production, has allowed us to minimise the time taken to reach and exceed targets. In order to do this, I first had to accept change and then become a catalyst for change for everyone involved in the production process. I have to say that the Lean Transformation of our employees and equipment has undoubtedly been the most striking aspect of the whole project. Now future changes will be lions to be tamed and not feared.”
(Fabrizio Borgonovo, head of production at the Valmadrera plant, Lean project Leader)
A scenario where Lean methodologies taken from the bestseller “Toyota Way. The 14 principles for the rebirth of the Italian industrial system ” (By J.Liker and L. Attolico, Hoepli 2014) and the increased flexibility provided were applied, allowing Husqvarna’s Italian plant to react to the danger of having production transferred out of Italy due to concerns over the plant’s competitiveness.